DE 10 2009 028 670 A1 disclosed a multi-stage transmission which is designed as a planetary transmission and which has nine forward gear ratios and one reverse gear ratio. The multi-stage transmission includes four planetary gear sets, eight rotatable shafts and six shift elements. A transmission input shaft of the multi-stage transmission is couplable by shift elements to different planetary gear set shafts of the planetary gear sets and thus constitutes a “free shaft.” Since the transmission input shaft is operatively connected directly to a component fixed to a housing, the activation energy required for the actuation of the shift elements can, e.g., be conducted directly from the housing into the transmission input shaft and by the transmission input shaft to the shift elements.
A disadvantage here is however that the transmission input shaft must provide not only the actuation of the shift elements but also further functionalities, such as lubrication of various components of the multi-stage transmission, a drive of a transmission pump, a bearing function for components arranged thereon and the like, as a result of which a transmission input shaft of said type must be designed with undesirably high structural complexity and is therefore characterized by a cumbersome manufacturing process.
A planetary transmission which is likewise designed with a free shaft is known from U.S. Pat. No. 8,545,362 B1, wherein the free shaft is neither the transmission input shaft nor the transmission output shaft. The free shaft of the planetary transmission is however disadvantageously arranged in the region between planetary gear sets, as a result of which an actuation of shift elements of the planetary transmission by the free shaft can be realized only with undesirably great effort.